Method and machine for filling bags of thermo-weldable material



METHOD AND MACHINE FOR FILLING BAGS OF THERMO-WELDABLE MATERIAL FiledJuly 15, 1957 R. ORSINI March 15, 1960 2 Sheets-Sheet 1 R. QRSINI March15, 1960 METHOD AND MACHINE FOR FILLING BAGS OF THERMO-WELDABLE MATERIAL2 Sheets-Sheet 2 Filed July 15, 1957 fthe line of operation of thepresser members.

This line of welding may belocated inside or outside "the line or"operation of presser members that areflused "to prevent leakage. 7 alonga line onthe inside of 'saidline of operation of ilnited States METHODAND MACHINE 1 R FlLLING BAGSGF THERNlfl-WELDABLE MATERIAL Ren firsini,Casablanca, Morocco, assignor to S. A. Pins. tus, Saint-Pierre,Frihourg, Switzerland, a corporation of Switzerland Application July 15,1957, Serial No. 572,325" Claims priority, application Morocco any 2%,1956 7 Claims. (cries-4'2 My invention has for its object a method iforfilling bags made of thermo-weldable material. in known methods,.-thefilling of'the' bags is accomplished-by means of nozzles or" alargecross-section which are fitted be tween the edges of the openingsof the bags. Ithas also been proposed to use hollow needles of a smallcross-sectional area to be set in position between said edges,

while yielding presser members prevent leakage fromthe bags between theedges of said openings, the bags being finally closed throughthermo-welding along a -line or in a zone of welding which is atsmalldistance from However, when the bagis'welded the presser members, it isessential to weld through the liquid or other filling material in thebags. In many cases this cannot be done. If the line of weldingis out-'l aientedlvlar. 159 9,

and it is then caused to sink by a length corresponding :to the lengthof a single bag, after which lower' and "tightlines and finally thesheath a further unitary length.

upper jaws are urged against the sheath so as to separate,

underneath the lowerjaw, the volume of liquid to be packed in the bagfrom the volume of liquid enclosed "in the upper part of the tubularsheath; this being done,

the small'amount of liquid lying between the two fluidtight lines isexhausted by means of a hollow needle ex- I tending through the upperfluidtight line :or in any other suitable manner, the Weld is executedbetween said fluidis caused to progressby In the case of pulverulent orsolid products to be packed in vacuo orinside' an inert atmosphere, ameasured amount 'ispreferably introduced intothesheath'only after anelementary progression of the latter; the upper jaw is then closed toform a fluidtightline while, vacu- "urn is applied and thereafter theinert gas is allowed to enter, the lower'jaw is closed to produce alower fluidtight line, vacuum is'prov'ided between the two jaws, and

the weld is produced between the latter.

lvly inventionhas also for its object a machine for the execution of theabove idisclosed method.

Further features of my improved method andv of the machine for executingsame will appear in the reading of-the following description of a numberof embodiment's, reference being made to the accompanying drawingsillustrating said embodiments and wherein: I

Fig. 1' is a sectional view illustrating a simpleer'nbodiment of theinvention. I T

Fig. 2 isa view corresponding to Fig. '1, after application of thepressure members forming the second fluid v tight line across a bag.

ing stepJ Fig. 4' is a cross-section through a modification of Fig. l..Fig. 5 is a plan viewof the arrangement according to Fig. 4. I

Fig. 6 is a perspective, partly sectional view of a first vention, theupper part of the bag is closedby two" spaced fluidtight lines, thefluid between these two fluid-f tight lines is sucked out and thewelding is performed.

between these two fluidtight lines. The outer fluidtight line may be thefluidtight line provided to prevent leakage between the nozzle or hollowneedle andthe opening of the bag to be filled already known in the oldprocesses, but it may be also a fluidtight line separating the liquidfilling a tubular sheath, which must be welded to form unitary doses,from the unitary dose to be, welded.

.The embodiment consisting in producing two fluidtight lines or applyingpressurealongtwo spaced linear zones, whether'in parallelism orotherwise, in exhausting the liquid orthe like fillingmaterialyand inproviding a line of weld between said'fluidtight lines, permits ofobtaining a continuous filling without resorting to hollow needles, therate of flow through which is necessarily low in the case of liquids asWell as in the case of solid or pasty materials. I

.In a preferred continuous operation, there is first formed in acontinuous manner immediately to the front lines between which areexecuted the transverse weld or welds, while suitable means are providedfor exhausting 'of the welding station, a tubular sheath, said sheatherr-' gaging said welding station extending transversely of the sheathand including two jaws forming two fluidtight embodiment of a machinefor the continuous filling with liquid of a string of bags.

Fig. 7 is a sectionalview of a modified embodiment of theweldi ng meansincorporated with Fig. 6.

Turningfto the embodiment illustrated in Figs. 1 to- 3, l used-twopresser members 1 provided with elastic fillings 2 made 'of spongerubber, for instance, in association with two further presser members 3located nearer the ,main part of the bag to be filled than the firstpresser members 1, said presser members 3 beingvmade of metalfor;instance. ="On'the other hand, heating electrodes4 "areinserted'between the presser members 1 and the presser members 3.- Thearrangement includes, further-- more, hollow needles 5 illustrated inFig. 1. The bag 6 open along its upper edge is first filled or itsfilling is brought to a finish and then, as shown in Fig. 2, the

Instead of using presser members providedwith an 1 elastic. filling, itis also possible toresort to-rigid presser members ,provided along theirsurfaces in contact with bers are used, as shown at '7.

In the empressermemthe bag recesses for housing the :needles. bodiment'illustrated in Figs. 4 and '5, such z'siazis Fig. 3 illustrates the sameembodiment during the weldj and res.

Movable presser members 7 and 9 may be provided only on one side of thelocation of the bag, while a single stationary presser member 8 ispositioned on the other side of said location, for cooperation with themovable presser members 7 and 9 and with the heating electrode 10. Ahollow needle is again used as shown at 11. The

modus operandi of this arrangement is similar to that described withreference to Figs. 1 to 3.

The presser member 9 may, according to a modification, assume-a movementin a direction parallel with .the axis of the needles, in which case thepresser member 9 is first shifted against the bag at the level of thelocation of the presser member 7 and it is thereafter shifted downwardlyso as to drive out the liquid enclosed inside the outer end of the bagand the electrode 10 is then caused to weld a line across the space thusprovided between the locations of the'presser members 7 and 9.

In the embodiment illustrated in Fig. 6, two sheets of plastic materialare welded along their vertical coop- .eratingedges by means of frictionwheels 13 so as to adapted in their turn to receive a reciprocatoryvertical movement along the guiding uprights 18.

The blocks 16 include each a body to which are secured, near their upperand lower edges, elements 1% and 1% respectively, forming jaws thatprovide fluid-tight lines of contact between opposing wall surfaces in abag. inside said body 16 and between the jaws 11% and i9!) is fitted awelding jaw 20 adapted to cooperate with an exactly similar jaw facingit on the other block so as to produce on the sheath at least one, butpreferably,

as illustrated, two transverse welds 21 spaced by a few millimeterswhereby two filled bags may be separated from one another between saidtwo lines of weld. The blocks are subjected to pressure by a cam or thelike control system acting on the push rods 22. A return spring 23associated with said push rods returns said blocks into their relativelyspaced position. I

Lastly, a hollow needle 24 is fitted inside the tubular sheath betweenthe upper jaws 19a. This needle has for its object to remove the liquidenclosed inside the sheath between the jaws 19a and'19b. It may beconnected with a pump. According to a preferred arrangement, the needlemay form itself the hollow rod or pipe for a suction pump and to thisend, it terminates at its upper end as a piston 25 slidingly engagingthe inside of a tubular body 26 against the action of a spring 27.

, The sheath being produced in a continuous manner and being filled withliquid up to a substantially constant height, the jaw-carrying blocks 16are caused to move nearer each other in their upper position, so as toproduce through the agency of the jaws 19a and 1% two transversefluidtight lines closing the sheath. The upper lluidtight line 19aprovides simultaneously a clamping of the needle 24. The liquidcontained in the section 28 of the sheath lying underneath saidfluidtight lines is thus separated from the liquid'in the upper sectionof the sheath or from that held between the two jaws 19a The jaws beginthen executing a downward movement over the guiding uprights l8 and theycarry along with them the needle 24 through which the liquid containedin the intermediate section of the sheath between the jaws is sucked outunder the action of the shifting of the piston 25 inside the stationarypump body 26. -.:....When all the liquid contained in said intermediatesection of the sheath between the jaws 19 has been sucked out intothepump body 26, the welding jaws 20 are subjected to pressure andprovide for transverse welding. After cooling of the welds, the jawblocks 16 move apart and rise into their original position whilesimultaneously the needle 24 is returned into its upper position by thespring 27, the liquid which has entered the body of the pump 26'returning then into the sheath above the finished bag.

In order that the tubular sheath may not assume a dangerous deformationunder the pressure'of the liquid column, and with a view to checking thevolume of liquid contained in each closed welded element or bag, thereis provided preferably underneath and also if required above the weldingjaws, vertical abutment plates 29 which limit the lateral deformation ofthe sheath, said abutment plates being illustrated in dotted lines inFig. 6.

The progression of the sheath may be produced under the action of thejaws 1% which act on a cold section of the thermo-plastic materialforming the, sheath or, preferably, through the agency of independentdriving members, which allows making the reciprocation of the membersproducing the transverse welds on the sheath independent of the frictionrollers producing the longitudinal welded seam of the sheath.

According to a further embodiment suiting more particularly the packingof solid material, the jaw blocks 16 are modified as illustratedcross-sectionally in Fig. 7. The sheath progresses then by a distancecorresponding tov the length of one bag and the product 30 to be packedis introduced into said sheath. The jaws close and apply under pressureover the sheath the elastic packings 31 to form a transverse fluidtightline. A push member 32 brings then the sectionof the sheath lyingunderneath said fluid-tight line and extending throughout the height ofthe jaws into contact with the suction grip 33. The latter is providedwith a peripheral channel connected through auxiliary channels 34 with asource of vacuum while a central needle 35 is connected also with thesource of vacuum and if required with a supply of inert gas. When thesheath is urged against the suction grip, the source of vacuum isconnected with the channel leading to said suction grip. The wall of thesheath is urged laterally with some considerable energy against saidsuction grip; it is perforated through the needle 35 in registry withthe latter; the air contained in the tubular sheath underneath theiluidtight line formed by the packings 31 is then sucked out.

Vacuum being applied, it is possible to send into the sheath an inertgas through connection between the channel feeding the needle and asupply of such a gas; the lower jaws 36 are then set in position so asto form a further fluid-tight line after which the needle 35 is causedto suck out the inert gas which may have been sent into the sheath andremains between the fluid-tight lines at 31 and 36; this being done, theheating jaws 37 are applied and the transverse welds are provided toeither side of tne needle 35.

The embodiments described hereinabove are capable of many modificationswithout this unduly widening the scope of the invention as defined inthe accompanying claims.

What I claim is:

l. A method of filling thermo-weldable bags, which method comprisesfilling at least partly with a fluid .a bag open at its upper end,applying pressure to bring opposite inner surfaces of the bag wall intofluid-tight contact with each other along two spaced lines adjacent saidupper end; removing from the space between said lines, fiuid with whichthe bag is filled; and welding together opposite surfaces of the bagbetween said spaced lines to form a leakproof seal for the bag.

2. A method of producing filled bags of thermo-weldable material, whichmethod comprises pouring liquid into a bag open at its upper end,producing two spaced fluid-tight lines of contact between oppositeinner, surend, sucking out the liquid remaining in the space he level,subjecting said sheath to pressure along two trans-1' verse linesunderneath said level to form two spaced fluidtight lines across the bagat predetermined intervals removing the liquid filling the section ofthe sheath contained between said two fluidtight lines thus formed and,

welding the sheath along a line of weld lying between the said twofluidtight lines.

. 4. A method of producing filled bags of thermo-wcldable material,which method comprises forming a tubular sheath of said material, in acontinuous manner with a measure of solid material, moving the sheath byone baglength, closing the sheath over said measure along a fluid-tightline of contact at an unvarying level, producing vacuum underneath saidline, introducing an inert gas underneath said line, subjecting thesheath to pressure along a line extending underneath the said fluidtightline to form a second lower fluid-tight line at a short distance fromthe first line, producing vacuum between the two fiuid-tight lines ofcontact, and welding the sheath along a line extending between the saidtwo fluid-tight lines. 1

5. A machine for producing a string'of bags of-thermoweldable materialfilled with a product, comprising means for welding along their lateraledges two sheets of thermos weldable material so as to form a sheath ofthermo- Weldable material along a vertical path, means for filling thissheath with liquid up to a predetermined level, blocks located on eitherside of the sheath at a predetermined point under the above fillingpredetermined level, jaws in superposed relationship carried by at leastone block in register with the sheath and means for urging said blockstowards each other to make said jaws produce fluid-tight lines ofcontact across the sheath, a further jaw carried by at least oneblockand facing the sheath and means wherethrough the last-mentioned jawproduces the transverse welding of the sheath between the saidfluidtight lines of contact.

6. A method of producing filled bags of thermo-weldable material, whichmethod comprises pouring solid material into a bag open at its upperend, producing an upper fluidtight line across the opening of the bag,applying vacuum to the bag underneath said upper fiuidtightline, feedingan inert gas into said bag, producing a lower fiuidtight line spaced ofthe upper one, applying vacuum to the part of the bag between both saidfluidtight lines and welding together opposite surfaces of the bagacross a further line extending between said fluidtight lines.

7. A method of filling thermo-weldable bags which method comprisesfitting at least one hollow tube between the edges of the opening of thebag, applying prespressure; to bring opposite inner surfaces of the bagwall into fiuidtight contact with each other along a second line spacedfrom and under said first line, re-

moving the fiuid in the space between said lines and welding togetheropposite surfaces of the bag between said spaced lines to form aleakproof seal for the bag.

' References Cited in the file of this patent UNITED STATES PATENTS2,145,941 Maxfield Feb. 7,

2,387,812 Sonneborn Oct. 30, 1945 2,430,995 Roos Nov. 18, 1947 2,672,2681954 Bower Mar. 16,

